反应详情

However, the composition of nickel and zinc in the nickel-zinc alloy layer 5 was purposely deviated from the range according to the present invention in which the content of nickel is 70 to 88 wt % and the content of zinc is the balance. Thus, for this nickel-zinc alloy layer 5, a pyrophosphate based solution was prepared using zinc pyrophosphate (ZnP2O7·3H2O), nickel sulfate (NiSO4·7H2O) and potassium pyrophosphate (K2P4O7) so that the solution had a composition with 1.0 g/l of zinc, 1.5 g/l of nickel and 100 g/l of potassium pyrophosphate, and in the solution at a liquid temperature of 30° C., the copper foil itself was made to undergo cathode polaraization with the use of a stainless plate for the counter electrode under conditions of current density of 1 A/dm2 and electrolysis time of 300 seconds, thereby providing an alloy composition with 1.14 g/m2 (59.1 wt %) of nickel and 0.79 g/cm2 (40.9 wt %) of zinc. The weight thickness of the nickel-zinc alloy layer 5 was 1.93 g/m2. In concurrence with this formation of the nickel-zinc alloy layer 5 on the nodular treatment side 4, 0.10 g/m2 of nickel-zinc layer was formed on the shiny side 6 of the untreated copper foil 2 as a corrosion prevention layer.

1. customat a liquid temperature of 30° C.
2. customelectrolysis time of 300 seconds